The improvements that are the subject of this patent application are the result of Applicant's continuing work on inventions disclosed in previous patent applications in his name. Applicant's issued patents are: U.S. Pat. No. 4,955,393 dated Sep. 11, 1990; and U.S. Pat. No. 4,983,334 dated Jan. 8, 1991. Pending applications are: U.S. Pat. No. 07/469,286 filed Jan. 24, 1990 now U.S. Pat. No. 5,082,007; and U.S. Pat. No. 07/780,545 filed Oct. 22, 1991, which has the benefit of U.S. Pat. No. 07/616,329 filed Nov. 21, 1990 and of U.S. Pat. No. 07/329,407 filed Mar. 27, 1989 all of these three applications now being abandoned.
The references cited in those applications constitute art that is known to Applicant, and a recently issued patent on the subject of mouthguards is U.S. Pat. No. 5,031,638 issued Jul. 16, 1991.
In Applicant's prior patent applications on the subject matter hereof, new and unique multi-layer (multi-laminar) mouthguard constructions are disclosed. Such multi-layer constructions provide significant improvement in mouthguard performance and features. In one aspect, the present invention relates to further improvements in multi-layer mouthguards, both as to the multi-layer structure thereof and to methods for making them. In another aspect, the invention relates to new and unique molding methods for fabricating mouthguards, particularly to: supporting a main body of a mouthguard within a cavity of a mold while a liner is molded onto the main body; and building up a multi-layer mouthguard one layer at a time by a process that the Applicant refers to as "pyramid molding". A further aspect of the invention relates to mouthguards that have an attaching strap for attachment, or tethering, to an article worn by the user of the mouthguard. Such an article may be a sports headgear, i.e. the face mask or face bar of a football helmet for example. A still further aspect of the invention relates to a lip protector that fits onto such an attaching strap and over the lips of the user.
Principles of the invention are not necessarily limited to a mouthguard as that word is commonly understood. Principles are applicable to intra-oral appliances associated with at least one dental arch, including impression trays for taking an impression of a dental arch and orthodontic splints.
Further aspects of the invention, along with other features, advantages and benefits will be seen in the ensuing description and claims which are accompanied by drawings. The drawings describe a presently preferred embodiment of the invention according to the best mode contemplated at the present time for carrying out the invention.